Note that WTC 7 was only hit by lighter debris and yet it suffered
more damage then buildings that got the brunt of the debris.

He also argued that had it been a controlled demolition and
a symmetrical collapse it would not have happened. But all the buildings in
the WTC complex were so damaged that they partially collapsed and/or had to
be destroyed. In fact, however, all that was required was a very energetic controlled
demolition; the symetry was there, it just exploded outwards more then a normal
demolition, which generally tries to keep debris in its own footprint. There
is also evidence suggesting there were explosives used in WTC
buildings 5 and 6.